Antibiotics and Drug Resistance

BiologyAQAEdexcelGCSEUnit: Infection & Response
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The basics

From Miracle Cure to Modern Crisis

From Miracle Cure to Modern Crisis

In 1928, Alexander Fleming returned to his laboratory to find something extraordinary: a patch of mould had grown on a petri dish of bacteria — and the bacteria around it had died. This chance discovery led to penicillin, the first antibiotic, which went on to save millions of lives from infections that had previously been fatal. It felt like medicine had won.

But the victory was not permanent. Since antibiotics came into widespread use in the 1940s, bacteria have been fighting back through the relentless engine of natural selection. Today, MRSA infections are difficult to treat in hospitals, some strains of tuberculosis resist multiple drugs, and the World Health Organisation warns that antibiotic resistance is one of the greatest threats to global health. The story of antibiotics is both one of medicine's greatest triumphs and one of its most pressing ongoing challenges.

What are antibiotics and what do they target?: Antibiotics are chemicals that kill bacteria or stop them from growing. They target structures that bacteria have but human cells do not, such as cell walls. Examples: penicillin, amoxicillin, streptomycin.
Key terms

Biology glossary

What are antibiotics and what do they target?
Antibiotics are chemicals that kill bacteria or stop them from growing. They target structures that bacteria have but human cells do not, such as cell walls. Examples: penicillin, amoxicillin, streptomycin.
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Preventing Antibiotic Resistance

Individual Actions:

  • Complete the course: Always finish prescribed antibiotics, even if feeling better
  • Don't share: Never share antibiotics with others
  • Don't save: Don't keep leftover antibiotics for future use
  • Don't pressure doctors: Accept that viral infections don't need antibiotics
  • Practice hygiene: Prevent infections through good hand hygiene

Healthcare Measures:

  • Appropriate prescribing - only when necessary
  • Infection control measures in hospitals
  • Rapid diagnostic tests to identify bacterial vs viral infections
  • Surveillance of resistance patterns
  • Isolation of patients with resistant infections

Agricultural Controls:

  • Reduce antibiotic use in livestock
  • Ban growth-promoting antibiotics in animal feed
  • Improve animal welfare to reduce disease
  • Alternative disease prevention strategies

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Quiz · Question 1 of 23

What do antibiotics kill or stop growing?

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